Hey there guys. I got my self a cheap rig from a buddy. Its a 2002 F-250 5.4L gasser. Its got a lot of miles on it but I got it for a good price. I am having an issue with it that I am not sure where to start checking things. I picked up the truck a couple weeks ago and its ran fine until today. I should specify I have been doing some maintenance things here and there to the truck. Changed fuel and air filters last night. Changed the cruise control disengagement switch and harness plug also.

 

After about 10 minutes on the freeway today the engine just cut out and died. Got pulled over, shut the key off. Cranked it over and she started right away like normal. Then it was fine the rest of the trip. We did about 30 minutes of slow forest service road driving and it ran fine through all of that. Then on the way home it died twice on the freeway. Both times it started right back up like normal.

 

I am thinking maybe a fuel pump issue. The old fuel filter was pretty well plugged. Maybe now that everything is free flowing the pump cant keep up at highway speeds? I have not checked fuel pressures or anything. I also dont think its a short or wiring problem somewhere otherwise it would have cut out on the forest service roads which were more bumpy than the freeway.

 

What do you guys think??

I had that same issue with a Ford truck I had. If I got on it hard going up hill the fuel pump couldn't keep up.  I would pull over and all it could do was sit there at an idle, I let it sit to catch up and then it would go again.

Did a fuel pump solve that problem? I think I am going to put a pressure gauge on the rail and watch it while I cruise down the freeway. Then I can see if its a fuel pressure problem or not.

I never got a chance to find out. After bringing it to a mechanic... I wasn't very wise in those days... he told me the V-8 engine was to small for the size truck so it was using up all the capacity the engine could give. I believed him and traded it in for a van. I think he wanted to steal it from me at a good price. Anyhow I'm sure it was the fuel pump going weak on it, them things are the most likelees on the list, if you know what I mean.

Well I put a fuel pressure gauge on it and drove down the freeway. Pressures held steady and it never died again. Still not sure if it was the fuel pump or not. I hate intermittent problems!!

 

Any idea where to go next?

Just a couple things I can think of;

  Dirt in the tank that gets in the way once in awhile.

  Sticky float valve, but hate to see you rebuild carb just on a possibility. Somehow see weather it's electrical or fuel related.

 

 I think next time it quits check spark .

 

 

I sure hope its not a float valve being this is fuel injected What throws me is it will start right back up again as soon as I get stopped. No sputtering or coughing. Just starts back up like normal. I would think its an intermittent short someplace but it has only done it at freeway speeds. We bounced around logging roads for a couple hours and it never died.

 

Its definitely got me stumped.

I would be hooking up a test fuel pressure gauge and route it to the windshield and watch the fuel pressure and see if it drops out. I know that if the rail pressure on fuel injection gets too low it will die out. It could be the fuel pump can't keep up with highway loads and dies out. 

1 minute ago, Mopar1973Man said:

I would be hooking up a test fuel pressure gauge and route it to the windshield and watch the fuel pressure and see if it drops out. I know that if the rail pressure on fuel injection gets too low it will die out. It could be the fuel pump can't keep up with highway loads and dies out. 

 

Way ahead of you there boss. I did that last night and drove down the freeway for about 45 minutes. Pressure held steady between 35-40 at the rail all the time. Interesting thing is it never died last night though. Maybe Ill leave that gauge on there until it dies again.

1 minute ago, Ilikeoldfords said:

 

Way ahead of you there boss. I did that last night and drove down the freeway for about 45 minutes. Pressure held steady between 35-40 at the rail all the time. Interesting thing is it never died last night though. Maybe Ill leave that gauge on there until it dies again.

 

 

You need to see what happens when it dies. You might look at the idea of using a Live Data tool like OBDLink and reviewing the data logs when it does die. Some vehicle may have fuel pressure as a sensor and most don't.

Alright. Well for now I will just leave my pressure gauge on it. If or when it dies I will be able to watch it. I have a pretty good code reader that can also see live data. I might plug that in and watch things whenever I take it down the highway again.

  I would swap the fuel pump relay with another relay in the PDC and Fords have a fuel pump inertia kill switch under the dash that you might want to check.  It's been my experience that a high pressure fuel pump will most likely fail on start up where the pump armature is binding and the voltage can't over come the drag.  The pump may or may not work if tapped on. 

  The problem may be in the ignition system with a failure on the primary side of the coils causing a general no spark condition.